Control strategies for maximizing renewable energy utilization in power systems

Environmental and economic challenges lead to the rapid growth of the renewable energy (RE) market in many countries. At a high level of RE sources (i.e. wind and solar) penetration, power systems face technical difficulties associated with the critical frequency stability and insufficient power reserves. The problem becomes particularly acute at penetration levels higher than 50 %, when conventional generation units are forced to operate at partial load, potentially resulting in premature equipment wear. Energy storage and demand-side management may offer solutions in the future, however, at the current stage, they incorporate substantial capital investment and complicate control system. This paper suggests a control strategy for maximum RE penetration, adopting a low load diesel application integrated with a small-capacity battery energy storage system. The strategy results in improved renewable energy utilization without overcomplicating the control architecture. Initially, a mathematical model is developed, then it is validated based on an isolated power system – a power system where penetration of RE already exceeds 50 % annually. Optimized control strategies are shown to deliver a 20 % increase in renewable energy penetration in comparison to conventional ones.